This invention relates to a system for controlling the timing of the operation of the various components of a plurality of individual sections of glass forming machinery.
Glass forming machines are typically made up of a plurality of individual sections each capable of manufacturing by itself glassware. The sections are operated in synchronism in such relative phase relationship as to permit the several sections to acquire gobs of molten glass for a single source in ordered sequence. Thus, as one of the sections is taking a gob from the gob feeder another section is delivering a finished article to an output conveyor and other sections are engaged in various forming steps intermediate the taking of a gob and the production of the finished ware.
In order to control the operation of the various functional components of each individual section of the glass forming machine, a means must be provided for actuating each of the elements in a pre-selected cyclic time format so that the operation of one element or component does not interfere with, but rather complements, the operation of the other components.
The several functional elements or components of the glass forming machine are typically driven by pneumatic pressure which is controlled by an electronic timing circuit. An example of prior art controllers utilizing electronic timing means may be found in Quinn et al, U.S. Pat. No. 3,762,907 and Kwiatkowski et al, U.S. Pat. No. 3,969,703, both of which are assigned to the common assignee herewith. Other examples of prior art electronic controllers may be found in Croughwell, U.S. Pat. No. Re. 29,188, and Mylchreest et al, U.S. Pat. No. 3,877,915. Each of these controllers typically includes a timing means for generating a machine cycle clock pulse train in synchronism with the operation of the machine being controlled wherein the cycle clock pulses provide an instantaneous indication of the time elapsed in each cycle of operation of the machine. In each individual section a storage unit such as a random access memory or a recirculating shift register stores the relative times in the machine cycles when each of the plurality of components of the machine are to be actuated. A comparator arrangement then compares the output of the pulse generator which indicates the time elapsed in each cycle with the stored values in the storage unit. When a comparison is made, an actuating signal is generated for indicating that the functioning of the machine component is to be either started, stoped or modified. To determine which machine component is to be actuated, an addressing means is provided which when enabled by the output of the comparator selects the particular component which is to be actuated at that time in the machine cycle. A component operating command is then provided to the appropriate component to thereby control the operation thereof. These electronic controlling systems include an arrangement for varying the time at which a particular machine component is to be actuated while the machine is operating. Further, as disclosed in the Mylchreest et al and Croughwell patents, the timing of certain machine components can be varied as a group. Thus, certain boundaries which define a group of machine components are established which relate to the thermodynamics of the glassware forming process. These boundaries permit the use of a computer or controller, appropriately programmed, to alter the boundaries by predetermined increments to vary machine operation and to improve the machine's efficiency. Further, these machines include systems for initiating a starting or stopping sequence at any time during the machine cycle, so that once a starting or stopping sequence is initiated, the machine is controlled according to a pre-selected starting or stopping cycle so that the machine can be safely and efficiently turned on or shut down.
Each of the aforementioned individual sections of the glass forming machine must be controlled in an interdependent cyclic phase relationship with respect to one another and, as is often the case, the modification of the timing of one unit may necessitate a change in the timing of another unit and, in addition, the relative timing sequence of all the units taken together may be modified dependent upon the type of glassware being formed, ambient conditions, etc. Accordingly, there is a need in the art for a simplified, operator control system for controlling the timing of the various IS machines. In order to do this, there must be a means for obtaining immediate access to all of the glass forming machine function timing information and in response thereto to permit automatic loading, storing, displaying and printing of glass machine function timing information.
It is therefore an object of this invention to provide a simplified arrangement for permitting an operator to control and modify the timing of the respective components of each of a plurality of individual section glass forming machines.